We invested heavily in contract testing between our microservices. The upfront cost was significant, but it eliminated an entire class of integration failures that had been causing 40% of our production incidents. Consumer-driven contracts caught breaking changes before they reached staging.
Data Integrity
Error handling deserves as much design attention as the happy path. We created a taxonomy of error types — retryable, user-fixable, operator-fixable, and fatal — and built standard handling patterns for each. Support tickets dropped by half because users finally got actionable error messages instead of generic 500 pages.
The Migration Path
Post-mortems without action items are just storytelling. We implemented a strict follow-up process: every post-mortem produces at most three concrete action items, each assigned to a specific person with a deadline. Items that don’t get done within two sprints get escalated or explicitly deprioritized.
Incident Post-Mortem
The hardest part of any migration is the data. Not the schema changes — those are mechanical. The real challenge is ensuring data integrity during the transition period when both old and new systems are running simultaneously and writes need to be consistent across both.
Database connection pooling was our biggest blind spot. Under normal load, direct connections worked fine. But during traffic spikes, the database would hit its connection limit and cascade failures across all services. A simple PgBouncer setup eliminated the issue entirely.
We ran a ‘dependency audit day’ where the entire team reviewed every third-party library in our stack. We removed 30% of our dependencies, updated critical security patches in others, and documented the rationale for keeping each remaining one. The build got 25% faster and our supply chain risk dropped measurably.
If you’re facing similar challenges, feel free to reach out. We’ve open-sourced several of the tools mentioned in this post and are happy to share more details about the ones we can’t release publicly.
Leave a Reply